1. Field of the Invention
This invention relates to a new novel method of manufacturing a thin film magnetic head assembly having a thin film magnetic transducer, substrate, and an electrical circuit means having a plurality of electrical conductors formed thereon, and more particularly to a method of attaching a plurality of electrical conductors to conductive leads of a plurality of thin film magnetic transducers wherein the electrical circuit means has leads having a diffusable conductive metal layer formed thereon. The method includes the steps of mounting the thin film transducer on the substrate, positioning the electrical conductors having the diffusible conductive metal coating in intimate contact with the conductive leads on the transducer, placing a quantity of insulating bonding material in the vicinity of the substrate, thin film transducer and electrical circuit member which form a subassembly, and heating and clamping and maintaining the so-clamped subassembly at a selected curing temperature for a preselected period of time to enable the insulating bonding material by capillary action to encapsulate the thin film magnetic transducer, the substrate and the electrical circuit member and to bond the same into an integral thin film head assembly.
2. Description of the Prior Art
It is known in the prior art to manufacture ferrite magnetic heads having at least two pole pieces formed of sintered ferromagnetic oxide material wherein the pole pieces are joined together with a short gap therebetween to form the transducing portion thereof and wherein the pole pieces are bonded together by glass. Typical of such known methods are the methods disclosed in U.S. Pat. Nos. 3,577,634; 3,246,383 and 3,024,318. Magnetic heads manfactured by the above known methods are combined with housings or ceramic sliders to form magnetic head assemblies used in apparatus, systems and equipment for storing and retrieving information in a recording media.
In order to produce smaller magnetic head assemblies, reduce the size of the gap forming the transducing portion of such magnetic head assemblies and to increase the recording densities and decrease the track widths of such magnetic head assemblies, new techniques have been developed to produce thin film magnetic transducers. Such thin film magnetic transducers can be fabricated by use of known vapor deposition, sputtering or plating techniques. Typical of such thin film magnetic transducers produced by use of the vapor deposition techniques are those disclosed in U.S. Pat. Nos. 3,867,368 and 3,846,841. Other thin film transducers are disclosed in U.S. Pat. Nos. 4,052,749 and 4,092,688.
With the rapid advance in techniques for manufacturing thin film magnetic transducers, the prior art includes many known techniques for fabricating the thin film magnetic head assemblies using thin film magnetic transducers. Typically, epoxy, glass bonding and other adhesives are used to form an integral bonded thin film magnetic head assembly.
One such glass bonding technique is disclosed in U.S. Pat. Nos. 4,143,458 and 4,191,983 to George W. Gibson, and assigned to the same Assignee as is this present invention.
It is also known in the art to fabricate a thin film assembly having a substrate, a superstrate and thin film magnetic transducer mounted therebetween wherein the thin film magnetic transducer includes conductive leads located interior to and extending between the substrate and superstrate. In fabricating such a thin film magnetic head assembly, the electrical leads are coated with a diffusable conductive metal coating. Also, the bonding is performed by use of an insulating bonding material, such as glass, which is selected of material which is electrically and magnetically compatible with the thin film magnetic transducer.
In order to obtain suitable bonding, the subassembly is heated and clamped which requires that the insulating bonding material have a melting point temperature which is below the thermal stress temperature at which at least one of the electrical characteristics and the magnetic characteristics of the thin film magnetic transducer are permanently distorted. As the subassembly is heated and clamped at a bonding temperature which is at a predetermined range, the insulating bonding material substantially fills the space between the transducer, substrate and superstrate and the area in the vicinity of the conductive leads of the transducer and the conductive leads of the connecting elements would be attached thereto through a diffusible conductive metal coating thereon to encapsulate and bond a thin film magnetic transducer, connecting elements and conductive leads having the diffused electrical connection therebetween into a thin film magnetic head assembly.